package org.andengine.opengl.vbo;

import android.opengl.GLES20;

import org.andengine.opengl.util.BufferUtils;
import org.andengine.opengl.vbo.attribute.VertexBufferObjectAttributes;
import org.andengine.util.system.SystemUtils;

import java.nio.FloatBuffer;

/**
 * Compared to a {@link LowMemoryVertexBufferObject}, the {@link HighPerformanceVertexBufferObject} uses <b><u>2x</u> the heap memory</b>,
 * at the benefit of significantly faster data buffering (<b>up to <u>5x</u> faster!</b>).
 *
 * @author Nicolas Gramlich <ngramlich@zynga.com>
 * @see {@link LowMemoryVertexBufferObject} when to prefer a {@link LowMemoryVertexBufferObject} instead of a {@link HighPerformanceVertexBufferObject}
 * <p/>
 * <p>(c) Zynga 2011</p>
 * @since 14:42:18 - 15.11.2011
 */
public class HighPerformanceVertexBufferObject extends VertexBufferObject {
    // ===========================================================
    // Constants
    // ===========================================================

    // ===========================================================
    // Fields
    // ===========================================================

    protected final float[] mBufferData;
    protected final FloatBuffer mFloatBuffer;

    // ===========================================================
    // Constructors
    // ===========================================================

    public HighPerformanceVertexBufferObject(final VertexBufferObjectManager pVertexBufferObjectManager, final int pCapacity, final DrawType pDrawType, final boolean pAutoDispose, final VertexBufferObjectAttributes pVertexBufferObjectAttributes) {
        super(pVertexBufferObjectManager, pCapacity, pDrawType, pAutoDispose, pVertexBufferObjectAttributes);

        this.mBufferData = new float[pCapacity];
        if (SystemUtils.SDK_VERSION_HONEYCOMB_OR_LATER) {
            this.mFloatBuffer = this.mByteBuffer.asFloatBuffer();
        } else {
            this.mFloatBuffer = null;
        }
    }

    public HighPerformanceVertexBufferObject(final VertexBufferObjectManager pVertexBufferObjectManager, final float[] pBufferData, final DrawType pDrawType, final boolean pAutoDispose, final VertexBufferObjectAttributes pVertexBufferObjectAttributes) {
        super(pVertexBufferObjectManager, pBufferData.length, pDrawType, pAutoDispose, pVertexBufferObjectAttributes);
        this.mBufferData = pBufferData;

        if (SystemUtils.SDK_VERSION_HONEYCOMB_OR_LATER) {
            this.mFloatBuffer = this.mByteBuffer.asFloatBuffer();
        } else {
            this.mFloatBuffer = null;
        }
    }

    // ===========================================================
    // Getter & Setter
    // ===========================================================

    public float[] getBufferData() {
        return this.mBufferData;
    }

    @Override
    public int getHeapMemoryByteSize() {
        return this.getByteCapacity();
    }

    @Override
    public int getNativeHeapMemoryByteSize() {
        return this.getByteCapacity();
    }

    // ===========================================================
    // Methods for/from SuperClass/Interfaces
    // ===========================================================

    @Override
    protected void onBufferData() {
        // TODO Check if, and how mow this condition affects performance.
        if (SystemUtils.SDK_VERSION_HONEYCOMB_OR_LATER) {
            // TODO Check if this is similar fast or faster than the non Honeycomb codepath.
            this.mFloatBuffer.position(0);
            this.mFloatBuffer.put(this.mBufferData);

            GLES20.glBufferData(GLES20.GL_ARRAY_BUFFER, this.mByteBuffer.capacity(), this.mByteBuffer, this.mUsage);
        } else {
            BufferUtils.put(this.mByteBuffer, this.mBufferData, this.mBufferData.length, 0);
            GLES20.glBufferData(GLES20.GL_ARRAY_BUFFER, this.mByteBuffer.limit(), this.mByteBuffer, this.mUsage);
        }
    }

    // ===========================================================
    // Methods
    // ===========================================================

    // ===========================================================
    // Inner and Anonymous Classes
    // ===========================================================
}
